Robot infantry get ready for the battlefield

"Please put down your weapon. You have 20 seconds to comply." So said the armed robot in Paul Verhoeven's 1987 movie RoboCop. The suspect drops his weapon but a fault in the robot's software means it opens fire anyway. Nearly two decades later, such fictional weapon-toting robots are looking startlingly close to reality - and New Scientist has discovered that some may eventually help to decide who is friend and who is foe.

Sometime in the coming months, chances are that we'll be seeing TV reports that an armed remote-controlled robot has been used in anger for the first time. "They will appear when they appear. I can't talk about when that may be," says Bob Quinn, general manager at Foster-Miller of Waltham, Massachusetts, whose machine-gun-equipped robot, called Sword, was certified safe for use by the US forces in June.